In order to establish whether functional homologies exist between the superior temporal gyrus ("auditory association cortex") or the monkey and Wernicke's Area in man, various auditory temporal processing abilities will be measured in monkeys by novel psychophysical procedures. The specific abilities to be studied in animals in this research program are viewed as necessary precursors of the capacity for language in man. Unilateral ablations of the superior temporal gyrus will be made, and the effects upon predetermined psychometric functions evaluated especially with regard to a suspected hemispheric asymmetry in monkeys for the mediation of certain time-dependent aspects of auditory experience. We will further attempt to establish a preliminary animal model which can relate deranged auditory-governed behaviors following unilateral ablations to the similar deficits known, in man, to follow damage to Wernicke's Area.